Symbiote Spell-Like Abilities

[Nifft]

I was looking through the Fiend Folio, and trying to figure out how to make use of the various Symbiotes.

Who is the caster for these sorts of abilities? Do they use the host's action?

For example, I'm looking at the Mind Leech in FF (p.217), and it's got a Psionics (Sp) block which lists suggestion, charm monster, and dominate person.

For example, there's a mind leech in a human's head, and a bugbear is nearby. The mind leech's charm monster effect is used. To whom is the target bugbear friendly?
- The human (and the target creature is unaware of the leech);
- The leech (and the target creature becomes aware of the leech);
- Both the human and the leech (somehow)?

Thanks!